```
(sine 12.15)
(p (sine 4.05))
(p (p (sine 1.35)))
(p (p (p (sine 0.45))))
(p (p (p (p (sine 0.15)))))
(p (p (p (p (p (sine 0.05))))))
(p (p (p (p (p 0.05)))))
(p (p (p (p 0.1495))))
(p (p (p 0.4351345505)))
(p (p 0.9758465331678772))
(p -0.7895631144708228)
-0.39980345741334

;可以看出一共调用了p五次。

;时间复杂度与空间复杂度都是`O(log n)`
```
